Dynamic generated form input wit same class validation doesn't' work

Question

I have a form that is dynamically generated on the click of add button. Say

<input type="text" id="date" class="date"/>
<button id="btn">Add+</button>

I did following

$('.date').each(function(){
   $(this).on('change', function(){
      if
      else
  })
})

In first form the validation is working fine but in form generated dynamically, it's not working.